检索结果-南通市图书馆

Chinese Journal of Mechanical Engineering 2024年第4期37卷 290-305页

作者： Chao Wang Tao Zhu bing Yang Shoune xiao Guangwu Yang State Key Laboratory of Rail Transit Vehicle System Southwest Jiao tong UniversityChengdu 610031China

The current research on the integrity of critical structures of rail vehicles mainly focuses on the design stage,which needs an effective method for assessing the service *** paper proposes a framework for predicting the remaining useful life(RUL)of in-service structures with and without visible *** hypothetical distribution and delay time models were used to apply the equivalent crack growth life data of heavy-duty railway cast steel knuckles,which revealed the evolution characteristics of the crack length and life scores of the knuckle under different fracture failure *** results indicate that the method effectively predicts the RUL of service knuckles in different failure modes based on the cumulative failure probability curves for different locations and surface crack *** study proposes an RUL prediction framework that supports the dynamic overhaul and state maintenance of knuckle fatigue cracks.

关键词： Heavy-duty railway Cast steel knuckle Remaining useful life Fatigue crack growth Hypothetical distribution

Non-volatile dynamically switchable color display via chalcogenide stepwise cavity resonators

在线全文

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2024年第1期7卷 16-27页

作者： Kuan liu Zhenyuan Lin bing Han Minghui Hong Tun Cao School of Optoelectronic Engineering and Instrumentation Science Dalian University of TechnologyDalian 116024China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361102China Institute of Laser Engineering Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China

High-resolution multi-color printing relies upon pixelated optical nanostructures,which is crucial to promote color display by producing nonbleaching colors,yet requires simplicity in fabrication and dynamic *** trisulfide(Sb_(2)S_(3))is a newly rising chalcogenide material that possesses prompt and significant transition of its optical characteristics in the visible region between amorphous and crystalline phases,which holds the key to color-varying ***,we proposed a dynamically switchable color printing method using Sb_(2)S_(3)-based stepwise pixelated Fabry-Pérot(FP)cavities with various cavity *** device was fabricated by employing a direct laser patterning that is a less timeconsuming,more approachable,and low-cost *** switching the state of Sb_(2)S_(3) between amorphous and crystalline,the multi-color of stepwise pixelated FP cavities can be actively *** color variation is due to the profound change in the refractive index of Sb_(2)S_(3) over the visible spectrum during its phase ***,we directly fabricated sub-50 nm nano-grating on ultrathin Sb_(2)S_(3) laminate via microsphere 800-nm femtosecond laser irradiation in far *** minimum feature size can be further decreased down to~45 nm(λ/17)by varying the thickness of Sb_(2)S_(3) *** switchable Sb_(2)S_(3) photonic devices can take one step toward the next generation of inkless erasable papers or displays and enable information encryption,camouflaging surfaces,anticounterfeiting,***,our work explores the prospects of rapid and rewritable fabrication of periodic structures with nano-scale resolution and can serve as a guideline for further development of chalcogenide-based photonics components.

关键词： tunable color displays Fabry-Pérot cavity resonators color printing chalcogenide materials

Intelligent Diagnosis of Highway Bridge Technical Condition Based on Defect Information

在线全文

学校读者我要写书评

暂无评论

Structural Durability & Health Monitoring 2024年第6期18卷 871-889页

作者： Yanxue Ma xiaoling liu bing Wang Ying liu Faculty of Maritime and Transportation Ningbo UniversityNingbo315211China School of Civil&Environmental Engineering and Geography Science Ningbo UniversityNingbo315211China

In the bridge technical condition assessment standards,the evaluation of bridge conditions primarily relies on the defects identified through manual inspections,which are determined using the comprehensive hierarchical analysis ***,the relationship between the defects and the technical condition of the bridges warrants further *** address this situation,this paper proposes a machine learning-based intelligent diagnosis model for the technical condition of highway ***,collect the inspection records of highway bridges in a certain region of China,then standardize the severity of diverse defects in accordance with relevant ***,in order to enhance the independence between the defects,the key defect indicators were screened using Principal Component Analysis(PCA)in combination with the weights of the building *** on this,an enhanced Naive Bayesian Classification(NBC)algorithm is established for the intelligent diagnosis of technical conditions of highway bridges,juxtaposed with four other algorithms for ***,key defect variables that affect changes in bridge grades are *** results showed that the technical condition level of the superstructure had the highest correlation with cracks;the PCA-NBC algorithm achieved an accuracy of 93.50%of the predicted values,which was the highest improvement of 19.43%over other *** purpose of this paper is to provide inspectors with a convenient and predictive information-rich method to intelligently diagnose the technical condition of bridges based on bridge *** results of this research can help bridge inspectors and even non-specialists to better understand the condition of bridge defects.

关键词： Highway bridges defects Naive Bayesian classification principal component analysis machine learning

Optimal SOC Headroom of Pump Storage Hydropower for Maximizing Joint Revenue from Day-ahead and Real-time Markets Under Regional Transmission Organization Dispatch

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 238-250页

作者： Yikui liu bing Huang Yang Lin Yonghong Chen Lei Wu Electrical and Computer Engineering Department Stevens Institute of TechnologyHobokenNJ 07030USA Midcontinent Independent System Operator Inc.CarmelIN 46032USA

In response to the increasing penetration of volatile and uncertain renewable energy,the regional transmission organizations(RTOs)have been recently focusing on enhancing the models of pump storage hydropower(PSH)plants,which are one of the key flexibility assets in the day-ahead(DA)and real-time(RT)markets,to further boost their flexibility provision *** by the recent research works that explored the potential benefits of excluding PSHs’cost-related terms from the objective functions of the DA market clearing model,this paper completes a rolling RT market scheme that is compatible with the DA ***,with the vision that PSHs could be permitted to submit state-of-charge(SOC)headrooms in the DA market and to release them in the RT market,this paper uncovers that PSHs could increase the total revenues from the two markets by optimizing their SOC headrooms,assisted by the proposed tri-level optimal SOC headroom ***,in the proposed tri-level model,the middle and lower levels respectively mimic the DA and RT scheduling processes of PSHs,and the upper level determines the optimal headrooms to be submitted to the RTO for maximizing the total revenue from the two *** case studies quantify the profitability of the optimal SOC headroom submissions as well as the associated financial risks.

关键词： Pump storage hydropower energy market state-of-charge(SOC) headroom market revenue tri-level problem

A non-probabilistic reliability topology optimization method based on aggregation function and matrix multiplication considering buckling response constraints

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 321-336页

作者： Lei WANG Yingge liu Juxi HU Weimin CHEN bing HAN Institute of Solid Mechanics School of Aeronautic Science and EngineeringBeihang UniversityBeijing 100191China Aircraft and Propulsion Laboratory Ningbo Institute of TechnologyBeihang UniversityNingbo 315100Zhejiang ProvinceChina State Key Laboratory of Navigation and Safety Technology Shanghai Ship and Shipping Research InstituteShanghai 200135China National Engineering Research Center of Ship&Shipping Control System Shanghai Ship and Shipping Research InstituteShanghai 200135China

A non-probabilistic reliability topology optimization method is proposed based on the aggregation function and matrix *** expression of the geometric stiffness matrix is derived,the finite element linear buckling analysis is conducted,and the sensitivity solution of the linear buckling factor is *** a specific problem in linear buckling topology optimization,a Heaviside projection function based on the exponential smooth growth is developed to eliminate the gray *** aggregation function method is used to consider the high-order eigenvalues,so as to obtain continuous sensitivity information and refined structural *** cyclic matrix programming,a fast topology optimization method that can be used to efficiently obtain the unit assembly and sensitivity solution is *** maximize the buckling load,under the constraint of the given buckling load,two types of topological optimization columns are *** variable density method is used to achieve the topology optimization solution along with the moving asymptote optimization *** vertex method and the matching point method are used to carry out an uncertainty propagation analysis,and the non-probability reliability topology optimization method considering buckling responses is developed based on the transformation of non-probability reliability indices based on the characteristic ***,the differences in the structural topology optimization under different reliability degrees are illustrated by examples.

关键词： buckling topology optimization aggregation function uncertainty propagation analysis non-probabilistic reliability

Martensitic transformation pathways and crystallographic orientation relationships in steel

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第7期174卷 74-84页

作者： Tian-Wei liu xiao-Lei Wu State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Martensite is one of the most important structures determining the ability to tailor the performance of steel and several other engineering *** previous studies,the face-centered cubic(FCC)to hexag-onal close-packed(HCP)(or body-centered cubic(BCC))martensitic transformation and the FCC to body-centered tetragonal(BCT)(or BCC)martensitic transformation during deformation and quenching were widely investigated;these transformations usually improve the plasticity and strength of steel,*** this work,detailed transmission electron microscopy(TEM)observations and electron diffraction pattern analyses of the BCT and BCC twins are performed along the[110],[131],and[¯153]zone *** transformation of BCT twins into BCC twins along the[131]zone axis is also analyzed through in situ heating during the TEM *** high-resolution TEM observations of mutually perpendicular BCT variants are consistent with the atomic arrangement obtained for the quenching pathway during the martensitic *** addition,different orientation relationships between austenite and marten-site are explained in terms of the atomic migration occurring during the deformation pathway and the quenching pathway of the martensitic transformation.

关键词： Body-centered tetragonal twin Martensitic transformation Steel Transmission electron microscopy Orientation relationship

Thermodynamic nature of black holes in coexistence region

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 27-32页

作者： Shao-Wen Wei Yu-xiao liu Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Provinceand Key Laboratory of Quantum Theory and Applications of Mo ELanzhou UniversityLanzhou 730000China Institute of Theoretical Physics&Research Center of Gravitation Lanzhou UniversityLanzhou 730000China

Studying the system state of coexistence regions will peek into to reveal microscopic interactions between different phases of a thermodynamic ***,there is no effective method to study thermodynamic nature of the coexistence black hole regions for the failure of the equation of *** at these coexistence states,in this work,we develop a general approach by introducing two new ratio *** first one is the ratio of the horizon radii of the saturated coexistence small and large black holes,and the second one measures that of the small black hole molecule number to the total molecule *** demonstrate that the first parameter can serve as an order parameter to characterize the first-order phase *** study also shows that the black hole state in the coexistence region is uniquely determined by these two introduced parameters bounded between 0 and *** results are quite significant in the analytical study of phase transition and the microscopic nature of black hole in the coexistence regions.

关键词： transition. state. thermodynamic

在线全文

学校读者我要写书评

暂无评论

未知参数小模数齿轮齿距和齿廓偏差视觉测量

光学精密工程 2021年第1期29卷 100-109页

作者：汤洁刘小兵李睿北京工业大学北京市精密测控技术与仪器工程技术研究中心北京100124

小模数齿轮齿槽间隙小,接触式测量难度高,且易损坏测头,本文主要研究基于视觉的未知参数小模数齿轮的齿距偏差和齿廓偏差测量。基于亚像素数字图像处理技术定位齿轮测量基准,即齿轮几何中心,并测量得到齿数、模数、齿顶圆直径和齿根圆直... 详细信息

小模数齿轮齿槽间隙小,接触式测量难度高,且易损坏测头,本文主要研究基于视觉的未知参数小模数齿轮的齿距偏差和齿廓偏差测量。基于亚像素数字图像处理技术定位齿轮测量基准,即齿轮几何中心,并测量得到齿数、模数、齿顶圆直径和齿根圆直径;依据齿轮精度标准ISO1328-1:2013中偏差项目定义,给出了基于视觉测量的齿轮齿距偏差和齿廓偏差评定方法,开发了小模数齿轮视觉测量数据处理软件。对模数为0.5 mm的渐开线圆柱直齿轮进行了齿距和齿廓偏差视觉测量试验,并与齿轮测量中心的测量结果对比,左右齿面测量结果的绝对误差最大为4μm,最小为1μm,评定齿轮精度等级均为8级。本文给出的未知参数小模数齿轮视觉测量系统和偏差评定方法可在一定范围内用于小模数齿轮测量。

关键词：视觉测量系统标定齿距偏差齿廓偏差齿轮参数测量

在线全文

学校读者我要写书评

暂无评论

钢铁企业订单变动执行的物料调配与跟踪算法

计算机集成制造系统 2008年第10期14卷 1978-1982页

作者：阎长罡刘晓冰大连交通大学机械工程学院辽宁大连116028 大连理工大学管理学院辽宁大连116024

在面向订单的钢铁企业生产中,物料的借用现象非常普遍,给物料跟踪带来了难度。为此,提出订单变动执行的物料调配与跟踪算法。在物料借用图模型的基础上,给出物料借用的平衡条件,分析了物料调配造成的各订单的交货期的变动情况,进而建立... 详细信息

在面向订单的钢铁企业生产中,物料的借用现象非常普遍,给物料跟踪带来了难度。为此,提出订单变动执行的物料调配与跟踪算法。在物料借用图模型的基础上,给出物料借用的平衡条件,分析了物料调配造成的各订单的交货期的变动情况,进而建立物料调配优化数学模型。该模型以库存费用和任务拖期费用最小为目标函数,可看作是单位运价同运输方案相关联的一类特殊"运输问题"的数学模型,给出了利用表上作业法求解此类特殊问题的关键步骤。最后,通过算例证明了该方法的有效性。

关键词：钢铁企业面向订单生产物料跟踪物料调配物料借用运输问题

Self-assembled high-entropy nitride multilayer coating

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第6期43卷 2876-2883页

作者： Xiang-Yu Zhang Yan liu Vasiliy Pelenovich xiao-Mei Zeng Jie liu Qiang Wan Alexander Pogrebnjak Long-Jian Xue Zhi-Wen Chen Yan Lei bing Yang School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China Hubei JiuFengShan Future Science and Technology Laboratory Wuhan 420000China Institute of Technological Sciences of Wuhan University Wuhan 430072China Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration Wuhan UniversityWuhan 430072China College of Engineering Huazhong Agricultural UniversityWuhan 430070China Sumy State University Sumy 40007Ukraine Institute of Materials Science Slovak University of Technology in BratislavaJána Bottu2591724 TrnavaSlovak Republic Shenzhen Research Institute of Wuhan University Shenzhen 518057China

The development of advanced materials and construction of multilayer structure contribute to enhancing the performance of protective coatings,further improving the industrial productivity and conserving *** this paper,the self-assembled high-entropy nitride(HEN)AlCrNbSiTiN multilayer coating was designed by harnessing the plasma distribution characteristics and depos-ited by arc ion plating using single target.

关键词： coating energy multilayer